As cases of the coronavirus are estimated to reach one million worldwide, medical professionals are bracing for the impact of a growing pandemic that’s flooding emergency rooms. While federal and local officials in the U.S. scramble for access to ventilators, experts at the Centers for Disease Control and Prevention (CDC) are exploring what exactly may be sending thousands of patients to intensive care units nationwide.

In a report from the CDC’s Morbidity and Mortality Weekly Report (MMWR) published Thursday, researchers conclude that Americans with diabetes, chronic lung disease and cardiovascular disease — all diseases linked to obesity — are at higher risk of experiencing a severe infection due to COVID-19.

The study analyzed more than 7,000 cases of coronavirus from February 12 to March 28. Out of the 457 individuals admitted to the ICU in that time, 358 — or 78 percent — reported having one or more underlying health conditions. Nearly 11 percent of the ICU-admitted individuals listed diabetes, followed by 9.2 percent reporting chronic lung disease and 9 percent reporting cardiovascular disease. Less than 30 percent of COVID-19 patients who recovered without hospitalization reported having an underlying health condition.

Stacy Brethauer, MD, bariatric surgeon at The Ohio State University Wexner Medical Center and a past-president of the American Society for Metabolic and Bariatric Surgery, says the research is concerning — not only for the general public but for medical professionals. “In general, patients with severe obesity are a more challenging population to manage in the intensive care setting as well and, for a variety of reasons related to their chronic disease state, will have less physiologic reserve if they develop any severe illness, particularly a respiratory infection like COVID-19,” Brethauer tells Yahoo Lifestyle.

For those in search of more information about what this means, here’s what you need to know.

Yahoo Lifestyle: Why is obesity a factor in the severity of COVID-19 infections?

​Stacy Brethauer, MD: Patients with the disease of obesity frequently have other obesity-related health conditions that could be associated with a more severe course if they are infected with COVID-19. While it is too early in this pandemic to have any strong data to support this, it is logical to think that many patients with obesity, especially severe obesity with a body mass index (BMI) over 40 kg/m2, will have health some additional conditions that could predispose them to a more severe course of illness with COVID-19.

YL: Can you elaborate on these conditions, and why they may be dangerous?

SB: For example, respiratory function in patients with obesity can be compromised from asthma, restrictive lung disease or obstructive sleep apnea. Cardiovascular disease is highly prevalent in patients with obesity and this may mean that those patients will have less physiologic reserve if cardiac complications of COVID-19 develop. [Physiologic reserve is defined as “the ability of an organ to successfully return to its original physiological state following repeated episodes of stress”].

YL: Are you concerned that the top three underlying conditions for COVID-19 ICU admissions in this study were related to obesity?

​SB: It does raise concern. While I haven't seen any data identifying obesity as an independent risk factor or predictor for hospitalization or mortality with COVID-19, it stands to reason that they would be at higher risk because these are diseases that are strongly associated with obesity. The majority of patients with obesity have at least one obesity-related comorbidity and type 2 diabetes and cardiovascular disease are among the most common.

YL: Are there other conditions listed that you want to flag?

SB: The other conditions flagged by the CDC paper include hypertension, hyperlipidemia, chronic kidney disease, cancer or a history of cancer, and non-rheumatoid arthritis in addition to diabetes, lung disease and heart disease. This list of chronic diseases describes the array of illness we see every day in our patients seeking treatment for obesity.

YL: Is it typical to see people with obesity have more severe reactions to respiratory illnesses?

​SB: The prevalence of pulmonary problems in patients with obesity is higher than for normal-weight individuals. Conditions like asthma, sleep apnea, restrictive lung disease and gastroesophageal reflux-related pulmonary issues all compromise the baseline pulmonary function of patients with obesity and will likely put them at some increased risk for serious illness with COVID-19. Again, there are many unanswered questions about specific risk factors that we don't know yet, but I think it is safe to say that patients with obesity and comorbidities that compromise their heart or lung function are likely going to be at higher risk for developing severe disease with COVID-19 much like the non-obese patients with those risk factors.